Process for preparing dyed collagen sausage casing

ABSTRACT

A brown dyed collagen casing containing chocolate as the dye. The chocolate can be incorporated into the casing by adding the chocolate to the collagen as the extrudable collagen gel is manufactured or may be applied to an extruded tubular casing before the casing is dried.

FIELD OF THE INVENTION

The present invention relates to edible collagen sausage casings,particularly to casings which are dyed with an edible dyestuff, and to aprocess for manufacturing such casings.

BACKGROUND OF THE INVENTION

Edible collagen sausage casings are made with collagen which is derivedfrom bovine hides or tendons. Such casings are widely used in themanufacture of many different sausage products including dried, smokedsausage. Dried, smoked sausage is widely available in various types suchas beef sticks, pepperoni, salami, thuringer and summer sausage. Thesesausages are usually filled in an edible food casing of animal originsuch as collagen. When the sausages are subject to the smoking process,the casing will pick up the color of the smoke. Unfortunately, the smokewill not uniformly color the casing, and therefore, there is a certainamount of nonuniformity of the casing which leads to an astheticallyunacceptable product. It is preferred to employ a dyed casing in themanufacture of this type of product. The dye imparts a uniform color tothe finished product and also prevents subsequent discoloration in theevent of rehydration of the casing which is a common problem with undyedcollage casings.

Prior art techniques for dyeing collagen casings have employed ediblecarriers in order to fix the dyestuff in the casing. For example, theprocess of U.S. Pat. No. 4,061,786 applies an edible dye to an ediblecarrier such as cellulose or starch powder, and then incorporates thepowder into the extrudable gel and extrudes the resulting admixture toform the dyed casing.

The process U.S. Pat. No. 3,961,085 employs an encapsulating agent toencapsulate the powder of the dyestuff and then introduces theencapsulated dye into the extrusion gel and then extrudes the gel into acasing.

Other methods of incorporating the dye include coating an extrudedcasing with the dye and fixing the dye on the surface of the casing withheat.

The above-mentioned processes were particularly useful when dyeing thecasing a reddish color as there are suitable food-grade red dyesavailable such as Annato or Bixin.

However, these dyes are not applicable if it is desired to dye thecasing a brownish color or a mahogany color. The mahogany color can becharacterized as brown with a trace of red. There are very fewfood-grade brown dyestuffs available which can be used in edible foodproducts.

SUMMARY OF THE INVENTION

Applicants have discovered that it is possible to produce a browncolored or dyed, edible collagen casing by the use of chocolate as thedyestuff. Chocolate is a naturally-occurring material which is edibleand when used in the present product and process does not impart anyflavor to the collagen casing, but imparts an adequate brown color sothe casing may be used for the purposes mentioned above. The chocolatein the casing will not be leached from the casing by water.

In addition, it is also possible to add other dyestuffs to the casing toprovide a mahogany color or hue to the casing.

DETAILED DESCRIPTION OF THE INVENTION

The collagen casings which can be dyed according to the present processare the well-known collagen sausage casings that are used in theproduction of edible sausages. Examples of such processes can be foundin U.S. Pat. Nos. 3,446,633; 3,123,482; and 3,535,125. The collagencontaining extrudable gels are generally prepared in the manner taughtin the above-mentioned patents, and the chocolate dye may be applied tothe casing by a number of different techniques. The chocolate may beincorporated into the extrudable gel when the extrudable gel is made.The gel can then be extruded in the normal fashion and processed throughthe normal manufacturing steps with no additional step necessary to fixthe dye in the casing.

The dye may also be prepared and injected into the extrudable gelimmediately prior to the point where the gel is extruded. If a mixer isemployed between the point of injection of the dye into the extrudablegel and the point where the gel is actually extruded, there will besufficient distribution of the dye throughout the gel to result in auniform color in the casing.

The dye may also be applied to the casing after the casing is extrudedand before or after the casing is dried but before the casing isshirred. The dye can be applied to the casing between the final washingstep in the manufacture of the casing and the drying step. The dye canbe sprayed on to the exterior surface of the casing or wiped on thesurface of the washed casing with a wiper and the casing is then driedin the normal manner. The dye can be applied to the dried casing in asimilar manner before the casing is shirred. The preferred process ofincorporating the dye into the casing is to mix the dye into thecollagen gel when the gel is being prepared.

The amount of chocolate in the finished casing may vary depending uponthe depth of dyeing that is desired in the casing. Generally, the levelof dye in the casing is between 1 and 15 percent based on the weight ofthe collagen solids in the casing. The preferred level of chocolate isbetween 5 and 10% chocolate. The chocolate used in the dye may be acommercially available chocolate liquor such as Peters #23, availablefrom Nestles Food Corporation, or broken orinoco chocolate which arereadily available materials. These materials are solids which must beliquified to incorporate the chocolate into the extrudable collagen gel.The chocolate can be melted in a heated vegetable oil such as corn oil,at a temperature of from about 150° to 160° F. to liquify the chocolate.It should be understood that other dyes may be added to the casing toproduce brown casing with different hues. The other dyes should also befood approved dyes. Yellow, orange and red dyes, in amounts of about 1%,or less, added to the chocolate dye will provide brown casing withvarious hues. For example, if the casing is to have a reddish hue,oleoresin of paprika, an Annato dye, carmine or other FDA approved foodcoloring dye such as FD&C Red No. 3 in the pure form or in the form of aLake may be used. The amount of the oleoresin of paprika employed wouldbe between 0.5 to 1%, preferably about 0.6% based on the weight of drycollagen solids. The amount of the Annato, carmine or red dye would be0.1 to 0.3%, preferably 0.2% based on the weight of collagen solids. Thereddish dye or dyes are first added to the hot corn oil and dispersedusing a high shear mixer. Broken orinoco is then added to the warm cornoil mixture until the chocolate melts. This liquid material is used as adye to dye the casing using any of the procedures which are set forthabove.

The brown dye is uniformly distributed throughout the casing and willnot leach out of the casing during the normal sausage manufacturingprocess or in the cooking of the sausage.

EXAMPLE 1 Hide Preparation

Hides from freshly slaughtered animals are trimmed and sided. They arewashed and soaked overnight in city water at 16° C. The following daythe hides are fleshed and weighed.

To a paddle vat with a capacity of 1100 gallons is added 3300 kilograms(kgs) of water and 1270 kgs of the fleshed hide. Forty-four and one-halfkgs of hydrated lime and 32 kgs of sodium sulfide are added to the vatand the paddle is alternately run and stopped over a 15-hour period. Thepaddle remains idle an additional 9 hours after which the vat isdrained, and the hides are washed in city water (16° C.) for 15 minutes.The paddle vat is refilled with a 1.0% lime solution, rotated 5 minutes,then allowed to rest an additional hour. The washed hides are then spliton a leather-splitting machine to recover the corium layer of the hide.

The corium layer is further processed to prepare the collagen forextrusion. A large wooden drum (capacity 3590 gallons) is charged with2600 kgs of hide corium, prepared as described above, and 1110 gallonsof water. The hide is washed with water in the drum for 30 minutes at aflow rate of 150 liters per minute. The wash is drained from the hidecorium, and the washed corium is treated in the drum with 1110 gallonsof water containing 13 kgs of ammonium sulfate for 2 hours, drained, andrefilled with the ammonium sulfate solution. After turning the hide anadditional 2 hours, the drum is drained and hide corium is washed withwater for 3 hours at a flow rate of 150 liters per minute. The water isagain drained from the hide corium, and the washed corium is treated inthe drum with 1110 gallons of water containing 18 kgs of hydrous citricacid and 24.5 kgs of sodium citrate dihydrate. The drum is rotated for16 hours with hourly adjustment of solution pH to maintain a solution pHof 4.6. At the end of this 16-hour treatment period, the citratesolution is drained, and the hides are washed for 4 hours in runningwater at a flow rate of 150 liters per minute. The hides are thenshredded and ground to a particle size of approximately one-fourth inch.The ground quarter-inch wide particles will hereinafter be referred toas "1/4 grind".

EXAMPLE 2 Dye Preparation

3.24 Kgs of corn oil are weighed into a stainless steel beaker andheated to 150°. 104 Grams of oleoresin of paprika are stirred into thecorn oil. 40 Grams of carmine powder are then added to the cornoil/paprika mixture. The combined ingredients are then mixed with a highshear mixer for 30 seconds to break up the lumps of carmine powder. 2.16Kgs of broken orinoco are then stirred into the warm corn oil mixture.As the chocolate melts, the temperature of the resulting mixture dropsto about 85° to 90° F. and the dye is now ready to be added to theextrusion gel.

EXAMPLE 3

40 Kgs of chipped ice and 331.72 liters of chilled water are put into adispersion tank. 2.20 Kgs of powdered cellulose is added, and a mixer isturned on at maximum speed. After 10 minutes, 72 kgs of the 1/4 grind ofExample 1 are added. The mixer is run at maximum speed for approximately20 minutes to break up the 1/4 grind lumps and soften the 1/4 grind.With the mixer running, the dye mixture of Example 2 is slowly pouredinto the dispersion at the area in the mixer of maximum turbulence toprevent lumps of dye from forming. The dye is mixed with the dispersionfor approximately 10 minutes. With the mixer off, 4.08 kgs ofhydrochloric acid (30%) are added. The mixer is again run at maximumspeed for 40 minutes.

The dispersion containing the dye is then passed through a high speedcutting mill where the hide particles are shredded to form a hydratedmass of fibrous character. The mixture is then pumped through a dairyhomogenizer, homogenized and transferred into a holding tank anddeaerated until use. Immediately prior to use, the dye gel is againpumped through a dairy homogenizer and deaerated prior to extrusion. Thegel is filtered and extruded into a collagen casing. The extrusion andsubsequent processing are carried out by the process described in U.S.Pat. No. 3,535,125. The casing had a mahogany color which was uniformthroughout the casing.

EXAMPLE 4

A series of samples of casing were prepared using the procedure setforth in Example 3. The percent of chocolate in the dye formulation wasvaried and the dye contained 0%, 1%, 5% and 10% chocolate. The color ofthe casing was measured using a MINOLTA Chroma Meter CR-100 and aMINOLTA Data Processor DP-100. The meter and the processor measure colorin different modes; the Yxy, L*a*b* and L*C*H°. The dye formulationcontained (percentages based on collagen solids).

15% corn oil

0.65% oleoresin of paprika

0.20% FD&C Red No. 3

varied Chocolate

The results are shown in the following table.

                                      TABLE I                                     __________________________________________________________________________           Yxy      L*a*b*     LCH°                                        % Choclate                                                                           Y  x  y  L  a   B   L  C  H                                            __________________________________________________________________________    0%     50.72                                                                            .3939                                                                            .3186                                                                            76.50                                                                            +31.95                                                                            +13.74                                                                            76.50                                                                            34.77                                                                            23.2                                         1%     59.27                                                                            .3804                                                                            .3384                                                                            80.33                                                                            +19.32                                                                            +18.42                                                                            80.33                                                                            26.49                                                                            43.6                                         5%     59.27                                                                            .3703                                                                            .3540                                                                            81.68                                                                             +9.13                                                                            +21.88                                                                            81.68                                                                            23.70                                                                            67.4                                         10%    56.62                                                                            .3709                                                                            .3571                                                                            79.96                                                                             +7.98                                                                            +22.58                                                                            79.96                                                                            23.94                                                                            70.6                                         __________________________________________________________________________

EXAMPLE 5

A casing was prepared as in Example 3. The dye formulation containedonly 10% chocolate and 15% corn oil but not other dye. The casing colorwas measured as in Example 4. The casing had the following color values:

    ______________________________________                                        Y     x      y       L*   a*   b*   L     C    H°                      ______________________________________                                        61.17 .3383  .3388   82.46                                                                              2.54 11.74                                                                              82.5  12.01                                                                              77.9                           ______________________________________                                    

EXAMPLE 6

As an indication of the color of the dyed casing of the presentinvention, the color of various commonly available items and the colorof the various casings were compared using the Minolta Color Meter as inExample 4. The casing samples were those from Examples 4 which alsocontained chocolate, oleoresin of paprika and FD&C Red No. 3 and Example5 which contained only chocolate. The results, using the LCH° scale areshown in the following table:

    ______________________________________                                                     L         C      H°                                       ______________________________________                                        White undyed casing                                                                          94.0        5.3    94.4                                        Manilla folder 90.5        23.3   88.6                                        Light brown egg                                                                              83.6        21.1   75.0                                        10% chocolate.sup.(1)                                                                        82.5        12.01  77.9                                        5% chocolate dye.sup.(2)                                                                     81.7        23.7   67.4                                        1% chocolate dye.sup.(2)                                                                     80.3        26.5   43.6                                        10% chocolate dye.sup.(2)                                                                    80.0        23.7   70.6                                        0% chocolate dye.sup.(2)                                                                     76.5        34.8   23.2                                        Medium brown egg                                                                             70.7        31.5   63.6                                        Dark brown egg 61.3        36.8   58.5                                        Kraft paper bag                                                                              59.8        21.4   72.3                                        Milk chocolate bag                                                                           40.7        7.3    42.7                                        Dark chocolate bar                                                                           36.9        4.1    29.7                                        ______________________________________                                         .sup.(1) From Example 5                                                       .sup.(2) From Example 4                                                  

I claim:
 1. A process for the manufacture of a dyed, unfilled, ediblecollagen casing, from an extrudable collagen gel comprising adding a dyeto the collagen in the casing, prior to the shirring of the casing, saiddye comprising chocolate liquefied in a vegetable oil, said casingcontaining from 1 to 15% chocolate based on the weight of the collagenin the casing, and drying the casing.
 2. The process of claim 1 in whichthe chocolate is added to the collagen during the preparation of theextrudable collagen gel.
 3. The process of claim 1 in which the dye alsocontains, based on the weight of the collagen, from 0.5 to 1% of Annatoand from 0.1 to 0.3% of Carmine.